Extensible flatback adhesive sheet

Abstract

The present invention provides an adhesive sheet that is extensible and conformable. The sheet comprises a non-creped flatback paper backing comprising cellulosic fibers and an elastomeric saturant and having an elongation at break of at least 8%; and an adhesive coating on at least a portion of at least one major surface of said backing. No mechanical means is used to generate extensibility or conformability in the backing of the adhesive sheet of the invention. The adhesive sheet combines all the advantages of a smooth flatback tape and the extensibility and conformability of a creped or microcreped tape.

What is claimed is: 
     
       1. An adhesive sheet, comprising: (a) a non-creped flatback paper backing comprising cellulosic fibers and an elastomeric saturant and having an elongation at break of at least 10% and   (b) an adhesive coating on at least a portion of at least one major surface of said backing, wherein no mechanical means is used to generate extensibility or conformability in said backing.     
     
     
       2. The sheet of claim 1 wherein the T g  of said saturant is less than -30° C. 
     
     
       3. The sheet of claim 1 wherein the T g  of said saturant is less than -45° C. 
     
     
       4. The sheet of claim 1 wherein the average surface roughness of said backing is less than about 7 μm. 
     
     
       5. The sheet of claim 1 wherein said saturant is a latex acrylic saturant. 
     
     
       6. The sheet of claim 1 wherein said adhesive is selected from the group consisting of polyacrylate; polyvinyl ether; polychloroprene; butyl rubber; butadiene-acrylonitrile polymer; thermoplastic elastomer; block copolymer; poly-alpha-olefin; amorphous polyolefin; silicone; ethylene-containing copolymer; polyurethane; polyamide; epoxy; polyvinylpyrrolidone and vinylpyrrolidone copolymer; polyesters; and mixtures of the above. 
     
     
       7. The sheet of claim 1 wherein said paper backing further comprises a barrier layer on at least one major surface. 
     
     
       8. The sheet of claim 1 further comprising a release coating on said paper backing opposite said adhesive coating. 
     
     
       9. The sheet of claim 1 wherein said adhesive coating is a pressure sensitive adhesive. 
     
     
       10. The sheet of claim 1 wherein said paper backing consists essentially of cellulosic fibers. 
     
     
       11. The sheet of claim 10 wherein said paper backing has an elongation at break of at least 12%. 
     
     
       12. The sheet of claim 9 having an elongation at break of at least 12%. 
     
     
       13. A method of masking a workpiece surface to facilitate painting a first area of the surface, said method comprising applying an adhesive sheet according to claim 1 to a second area of the surface. 
     
     
       14. A die-cut masking assembly comprising: (a) at least one sheet of a non-creped flatback paper backing of a predetermined design or configuration wherein said paper backing comprises cellulosic fibers and an elastomeric saturant and has an elongation at break greater than 10%;   (b) an adhesive coating on at least a portion of at least one major surface of said paper backing, and   (c) a release liner to which the adhesive composition is releasably adhered, wherein no mechanical means is used to generate extensibility in the backing.     
     
     
       15. A method of masking a workpiece surface to facilitate painting a first area of said surface, said method comprising applying a die-cut masking assembly according to claim 14 to a second area of said surface. 
     
     
       16. A method of making an adhesive tape comprising coating an adhesive onto at least a portion of at least one side of a non-creped flatback paper backing containing an elastomeric saturant and having an elongation at break greater than 10%, wherein no mechanical means is used to generate extensibility in the backing.